I don't mean that he's part of a political machine, although he is arguably a member of a few nascent operations in town, from the old-school Democratic Party establishment to the morphing amalgam of groups pushing what he calls a "livability" agenda. I mean that Supervisor Wiener, who represents District 8, is a machine — almost robotic in his tireless, 24/7 engagement with all things political.

In just two years on the board, he's become one of the most productive legislators in the city, courting controversy and taking on issues others had ducked. He is relentless in his quest to make government run more efficiently. He's affable, mild-mannered and accessible, often willing to work with opponents — but he has an agenda for the city that he pursues aggressively.

Perhaps more than anyone at City Hall, Wiener embodies the current political zeitgeist in San Francisco, with its emphasis on civility and private-sector job creation. He isn't the most powerful person in city government, but he's playing an outsized role in shaping the city's future — and that will only grow this week as he assumes the chair of the board's Land Use Committee.

Wiener defies easy labels. Critics who call him an uncaring conservative aren't quite right, and it's equally tough to simply accept the "urbanist" and "good liberal Democrat" labels that Wiener applies to himself. And it's hard to pin Wiener down on what sort of city he envisions, except for one with minimal bureaucracy where the trains and buses run on time.

In his City Hall office, where the walls contain little artwork, just the occasional reminder of past political episodes (like the framed Guardian butt cover from when he banned the nudists in the Castro from putting their bare asses on benches), he was happy to talk to me at length about policy. But he had less to offer on who he thinks this city is for — about who should be able to stay here, and who has to leave. He talks about preserving a safety net — but not about pushing back against gentrification and displacement with any tools up to the task.

In the end, his focus is on making government and the city's infrastructure work well for those who are able to live in a city that's become openly hostile to low-income and working-class people. He's an agent of change — but his change is disturbing to progressives. He's steadily moving legislation that makes it more difficult to counter trends that are gentrifying and sterilizing the city.

A BIT OF A NERD

Born in Philadelphia and raised mostly in the small, conservative New Jersey town of Turnersville, the young Scott Wiener always felt one step removed from his surroundings. So he poured himself into his studies. "I was always a bit of a nerd. I'll admit I was voted most studious in high school," Wiener said.

What social life he had centered around his synagogue in a Christian-dominated community. His parents — dad an optometrist, mom running his practice — were "very partisan Democrats" in a Republican county. Although they weren't very politically active, Wiener's earliest political memory is the 1980 presidential election that brought Ronald Reagan to power: "Our house was like a place of mourning."

Involvement in Democratic Party politics seemed to just flow from his academic life, interning with a member of Congress as a teenager and then helping form a Democratic Club when he attended Duke University, which devoted itself to campaigning against then-Sen. Jesse Helms when Wiener was a sophomore.

Coming out as a gay man at the age of 20 wasn't terribly traumatic in a family where his cousin and aunt were lesbians. His main concern was whether it might hinder his plan to run for president of his fraternity, the Jewish Alpha Epsilon Pi, but he won that election anyway.